| Parameter |
Value |
| Designation |
C/2023 S2 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2023-10-15T09:03:22.020480Z |
| Orbit solution date (soln_date, UTC) |
2024-06-06T23:12:32Z |
| Obs used |
392 |
| NEO |
- |
| M1 |
14.500 |
| K1 |
25.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2023-09-28T23:40:21.590400Z |
| Discovery magnitude (MPC) |
15.15 o |
| Discovery observatory (MPC) |
W68 · ATLAS Chile, Rio Hurtado |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2023-10-11.0000000 |
| e |
0.99288676 |
| q (au) |
1.067716 |
| a (au) |
150.102592 |
| i (deg) |
20.485436 |
| Ω (om, deg) |
230.562176 |
| ω (w, deg) |
78.109160 |
| M (ma, deg) |
359.997654 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.113 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.113 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.998 |
| k |
1.000 |
| δ90 |
10.000 |
| Parameter |
Symbol |
Range |
Description |
| Absolute magnitude at 1 AU from Sun and Earth |
H0 |
-5 to 20 |
Intrinsic brightness of the comet |
| Photometric slope parameter |
n |
2 to 6 |
Rate of brightness change with heliocentric distance |
| Forward scattering asymmetry factor |
gf |
0.8 to 1 |
Degree of forward scattering |
| Backward scattering asymmetry factor |
gb |
-1 to -0.5 |
Degree of backward scattering |
| Partitioning coefficient |
k |
0.8 to 1 |
Ratio between forward/backward scattering contributions |
| Dust-to-gas brightness ratio |
δ90 |
1 to 10 |
Relative contribution of dust scattering to gas emission |
Reference: EPSC-DPS2025-160
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
05:47:16.02 |
+11:51:06.9 |
HIP 27453 |
23.97 |
| 2026-06-01 12:00 |
05:47:28.53 |
+11:51:12.5 |
HIP 27453 |
21.11 |
| 2026-06-02 00:00 |
05:47:41.04 |
+11:51:17.8 |
HIP 27453 |
18.32 |
| 2026-06-02 12:00 |
05:47:53.57 |
+11:51:22.8 |
HIP 27453 |
15.63 |
| 2026-06-03 00:00 |
05:48:06.11 |
+11:51:27.6 |
HIP 27453 |
13.10 |
| 2026-06-03 12:00 |
05:48:18.67 |
+11:51:32.0 |
HIP 27453 |
10.86 |
| 2026-06-04 00:00 |
05:48:31.23 |
+11:51:36.1 |
HIP 27453 |
9.12 |
| 2026-06-04 12:00 |
05:48:43.80 |
+11:51:39.9 |
HIP 27453 |
8.21 |
| 2026-06-05 00:00 |
05:48:56.39 |
+11:51:43.5 |
HIP 27453 |
8.41 |
| 2026-06-05 12:00 |
05:49:08.98 |
+11:51:46.7 |
HIP 27453 |
9.64 |
| 2026-06-06 00:00 |
05:49:21.58 |
+11:51:49.6 |
HIP 27453 |
11.59 |
| 2026-06-06 12:00 |
05:49:34.19 |
+11:51:52.2 |
HIP 27543 |
10.50 |
| 2026-06-07 00:00 |
05:49:46.81 |
+11:51:54.6 |
HIP 27543 |
9.20 |
| 2026-06-07 12:00 |
05:49:59.43 |
+11:51:56.6 |
HIP 27543 |
8.84 |
| 2026-06-08 00:00 |
05:50:12.06 |
+11:51:58.3 |
HIP 27543 |
9.51 |
| 2026-06-08 12:00 |
05:50:24.70 |
+11:51:59.7 |
HIP 27543 |
11.04 |
| 2026-06-09 00:00 |
05:50:37.34 |
+11:52:00.8 |
HIP 27543 |
13.13 |
| 2026-06-09 12:00 |
05:50:49.99 |
+11:52:01.6 |
HIP 27543 |
15.55 |
| 2026-06-10 00:00 |
05:51:02.64 |
+11:52:02.1 |
HIP 27543 |
18.18 |
| 2026-06-10 12:00 |
05:51:15.30 |
+11:52:02.3 |
HIP 27543 |
20.94 |
| 2026-06-11 00:00 |
05:51:27.96 |
+11:52:02.2 |
HIP 27641 |
22.92 |
| 2026-06-11 12:00 |
05:51:40.62 |
+11:52:01.8 |
HIP 27820 |
22.72 |
| 2026-06-12 00:00 |
05:51:53.28 |
+11:52:01.0 |
HIP 27820 |
19.66 |
| 2026-06-12 12:00 |
05:52:05.95 |
+11:52:00.0 |
HIP 27820 |
16.60 |
| 2026-06-13 00:00 |
05:52:18.62 |
+11:51:58.6 |
HIP 27820 |
13.57 |
| 2026-06-13 12:00 |
05:52:31.28 |
+11:51:57.0 |
HIP 27820 |
10.57 |
| 2026-06-14 00:00 |
05:52:43.95 |
+11:51:55.0 |
HIP 27820 |
7.64 |
| 2026-06-14 12:00 |
05:52:56.61 |
+11:51:52.8 |
HIP 27820 |
4.93 |
| 2026-06-15 00:00 |
05:53:09.28 |
+11:51:50.2 |
HIP 27820 |
3.08 |
| 2026-06-15 12:00 |
05:53:21.94 |
+11:51:47.3 |
HIP 27820 |
3.71 |
| 2026-06-16 00:00 |
05:53:34.60 |
+11:51:44.1 |
HIP 27820 |
6.10 |
| 2026-06-16 12:00 |
05:53:47.25 |
+11:51:40.6 |
HIP 27820 |
8.93 |
| 2026-06-17 00:00 |
05:53:59.91 |
+11:51:36.8 |
HIP 27924 |
9.82 |
| 2026-06-17 12:00 |
05:54:12.55 |
+11:51:32.7 |
HIP 27924 |
7.50 |
| 2026-06-18 00:00 |
05:54:25.19 |
+11:51:28.3 |
HIP 27924 |
5.93 |
| 2026-06-18 12:00 |
05:54:37.83 |
+11:51:23.6 |
HIP 27924 |
5.76 |
| 2026-06-19 00:00 |
05:54:50.46 |
+11:51:18.5 |
HIP 27924 |
7.09 |
| 2026-06-19 12:00 |
05:55:03.08 |
+11:51:13.2 |
HIP 27924 |
9.29 |
| 2026-06-20 00:00 |
05:55:15.69 |
+11:51:07.5 |
HIP 27924 |
11.89 |
| 2026-06-20 12:00 |
05:55:28.30 |
+11:51:01.6 |
HIP 27924 |
14.68 |
| 2026-06-21 00:00 |
05:55:40.89 |
+11:50:55.3 |
HIP 27924 |
17.56 |
| 2026-06-21 12:00 |
05:55:53.48 |
+11:50:48.8 |
HIP 28067 |
19.61 |
| 2026-06-22 00:00 |
05:56:06.06 |
+11:50:41.9 |
HIP 28067 |
19.41 |